In order to meet wireless data traffic demands, which have increased since the commercialization of a 4th-generation (4G) communication system, efforts to develop an improved 5G communication system or a pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is called a beyond-4G-network communication system or a post LTE system.
In order to achieve a high data transmission rate, an implementation of the 5G communication system in an mmWave band (for example, a 60 GHz band) is being considered. In the 5G communication system, technologies such as beamforming, massive multi-input multi-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna technologies are being discussed to mitigate a propagation path loss in the mmWave band and increase propagation transmission distance.
Further, the 5G communication system has developed technologies such as an evolved small cell, an advanced small cell, a cloud radio access network (RAN), an ultra-dense network, device-to-device communication (D2D), a wireless backhaul, a moving network, cooperative communication, coordinated multi-points (CoMP), and received interference cancellation to improve the system network.
In addition, the 5G system has developed advanced coding modulation (ACM) schemes such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), and advanced access technologies such as filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA).
Meanwhile, smart devices, such as smart phones, tablets, smart watches, and wearable devices are showing growth. These smart devices include at least one type of cellular capability, such as 2G-based GSM, 3G-based UMTS/CDMA or 4G-based LTE, WiMAX, and the like. In addition, some of these smart devices are equipped with proximity radio capability (such as Bluetooth, Wi-Fi, etc.) which can operate in unlicensed frequency spectrum of 2.4 GHz or 5.0 GHz. With one or more radio capability equipped on such smart devices, they are able to connect to the internet to gain access to multitude of applications like audio/video streaming, navigation maps, social networking applications, games and plethora of over the top (OTT) services/applications in addition to operator/service provider services. In addition, from a user's point of view, the smart device that the user holds is not limited to one type of smart device, and smart phones, smart watches, tablets or simply a group of smart devices may exist near the user. Further, from user perspective ownership of such smart device is not restricted to one type of smart device where a user owns a smartphone, a smartwatch, a tablet or simply a group of smart devices are always present in the vicinity of the user. When the user is on the move both the operator/service provider services and the OTT services are available independently on the multiple smart devices through the cellular radio interface provided each smart device has independent SIM/USIM.
In addition, if the smart devices are equipped with Wi-Fi radio capability, the smart device can be connected to a wireless LAN (WLAN) access point (AP) to access OTT services. Typically, when a user is located at home, in an office environment, or in a place where the WLAN AP is installed, Wi-Fi-based radio capability are used to access OTT services on the smart device. In this case, operator and service provider services, such as voice calls and SMS, are provided through the cellular capability of the smart device. In addition, it is possible to provide integrated access to the operator's or service provider's cellular network and WLAN APs using the same subscription information stored in the SIM/USIM in the smart device.
The multiple smart devices associated with the same user having cellular radio capability may have individual subscriber identity module (SIM) so that independent data sessions can occur on the radio interface with the cellular network. For ease of handling billing related information and avoiding multiple data plans for multiple devices the user may wish to link the multiple devices so that unified billing and unified data plan is provided by the operator/service provider. The linking of plurality of cellular device(s) in core network can be based on unique identifiers associated with linked devices. Examples of such unique identifiers associated with the devices are: international mobile subscriber identity (IMSI) or international mobile equipment identity (IMEI) or globally unique temporary identity (GUTI). Such linking information of smart devices associated with same user or different users belonging to a group (e.g., family members like husband, wife and children) is typically maintained in the core network primarily in the home subscriber server (HSS) for providing unified billing. The linking information of smart devices can be additionally fetched at other core network elements like mobility management entity (MME) or Policy and charging rules function (PCRF) for other purposes apart from billing.